Health plans may change with time. Know what to expect and how to respond with these tips on how to avoid unexpected changes.

Since Kristen Catton started taking the drug Gilenya two years ago, she’s had only one minor relapse of her multiple sclerosis, following a bout of the flu.

She can walk comfortably, see clearly and work part time as a nurse case manager at a hospital near her home in Columbus, Ohio. This is a big step forward; two drugs she previously tried failed to control her physical symptoms or prevent repeated flare-ups.

This year, Catton, 48, got a shock. Her health insurance plan changed the way it handles the payments that the drugmaker Novartis makes to help cover her prescription’s cost. Her copayment is roughly $3,800 a month, but Novartis helps reduce that out-of-pocket expense with payments to the health plan. The prescription costs about $90,000 a year.

Those Novartis payments no longer counted toward her family plan’s $8,800 annual pharmacy deductible. That meant once she hit the drugmaker’s payment cap for the copay assistance in April, she would have to pay the entire copayment herself until her pharmacy deductible was met.

Catton is one of a growing number of consumers taking expensive drugs who are discovering they are no longer insulated by copay assistance programs that help cover their costs. Through such programs, consumers typically owe nothing or have modest monthly copayments for pricey drugs because many drug manufacturers pay a patient’s portion of the cost to the health plan, which chips away at the consumer’s deductible and out-of-pocket maximum limits until the health plan starts paying the whole tab.

Under new “copay accumulator” programs, that no longer happens.

In these programs, the monthly copayments drug companies make don’t count toward patients’ plan deductibles or out-of-pocket maximums. Once patients hit the annual limit on a drugmaker’s copay assistance program, they’re on the hook for their entire monthly copayment until they reach their plan deductible and spending limits.

Catton put the $3,800 May copayment on a credit card. She knows her insurer will start paying the entire tab once she hits the pharmacy deductible. But, she said, she can’t afford to pay nearly $9,000 a year out-of-pocket for the foreseeable future.

“I’m talking to my doctor to see if I can I take it every other day,” she said. “I guess I’m winging it until I can figure out what to do.”

Drug copay assistance programs have long been controversial.

Proponents say that in an age of increasingly high deductibles and coinsurance charges, such help is the only way some patients can afford crucial medications.

But opponents say the programs increase drug spending on expensive brand-name drugs by discouraging people from using more cost-effective alternatives.

Switching to a cheaper drug may not be an option, said Bari Talente, executive vice president for advocacy at the National Multiple Sclerosis Society.

“Generally the multiple sclerosis drugs are not substitutable,” she said. “Most have different mechanisms of action, different administration and different side effect profiles.” Generics, when they’re available, are pricey too, typically costing $60,000 or more annually, she said.

Most MS drug annual copay assistance limits, if they have them, are between $9,000 and $12,000, Talente said.

Employers argue that the drug copayment programs are an attempt to circumvent their efforts to manage health care costs. For example, employers may try to discourage the use of a specialty drug when there’s a lower-cost drug available by requiring higher patient cost sharing.

There’s also the issue of fairness.

“From an employer perspective, everyone under the plan has to be treated the same,” said Brian Marcotte, president and CEO of the National Business Group on Health (NBGH), which represents large employers.

If someone needs medical care such as surgery, for example, that person doesn’t get help covering his deductible, while the person with the expensive drug might, he said.

According to an NBGH survey of about 140 multistate employers with at least 5,000 workers, 17 percent reported they have a copay accumulator program in place this year, Marcotte said. Fifty-six percent reported they’re considering them for 2019 or 2020.

If there is no comparable drug available, drug copayment programs may have a role to play if they can be structured so that participating patients are paying some amount toward their deductible, Marcotte said. But, he said, assistance programs for drugs that are available from more than source, such as a brand drug that is also available as a generic, shouldn’t be allowed.

In 2016, 20 percent of prescriptions for brand-name drugs used a drug copay assistance coupon, according to an analysis by researchers at the USC Schaeffer Center for Health Policy and Economics. Among the top 200 drugs based on spending in 2014, the study found that 132 were brand-name drugs, and 90 of them offered copay coupons. Fifty-one percent of the drugs with copay coupons had no substitute at all or only another brand drug as a close therapeutic substitute, the analysis found.

Advocates for people with HIV and AIDS say copay accumulators are cropping up in their patients’ plans and beginning to cause patients trouble. Drugs to treat HIV typically don’t have generic alternatives.

The biggest impact for the community their organizations serve may be for PrEP, a daily pill that helps prevent HIV infection, said Carl Schmid, deputy executive director at the AIDS Institute, an advocacy group. A 30-day supply of PrEP (brand-name Truvada) can cost nearly $2,000. Drug manufacturer Gilead offers a copay assistance program that covers up to $3,600 annually in copay assistance, with no limit on how much is paid per month.

“They’re at risk for HIV, they know it and want to protect themselves,” Schmid said. “It’s a public health issue.”

Earlier this month, the AIDS Institute was among 60 HIV organizations that sent letters to state attorneys general and insurance commissioners across the country asking them to investigate this practice, which has emerged in employer and marketplace plans this year.

Compounding advocates’ concerns is the fact that these coverage changes are frequently not communicated clearly to patients, Schmid said. They are typically buried deep in the plan documents and don’t appear in the user-friendly summary of benefits and coverage that consumers receive from their health plan.

“How is a patient to know?” Schmid asks. They learn of the change only when they get a big bill midway through the year. “And then they’re stuck.”